The present invention relates to a semiconductor device and a method of fabricating the same, and more particularly, to technology for preventing device failure due to metal ion contamination by forming a dummy active region for gathering of metal ions.
Three-dimensional (3D) stacking technology in package technology of semiconductor integrated circuits has been developed to reduce dimensions of electronic devices, increase packing density of the electronic devices, and improve performance of the electronic devices. The 3D stacked package is a package in which chips having the same storage capacities are stacked and conventionally referred to as a stack chip package.
Stack chip package technology has an advantage of reduced fabrication cost due to a simplified process and mass production. However, stack chip package technology has the disadvantage of a lack of space for electrical connections inside the package due to an increase in the number of stacked chips and a chip size.
That is, the existing stack chip package is fabricated to have a structure in which bonding pads of each chip and conductive circuit patterns of a substrate are electrically connected through wires in a state in which a plurality of chips are attached in a chip attachment region of the substrate. Therefore, a space for wire bonding and an area for the circuit patterns connected to the wires are necessary and thus the dimension of the semiconductor package becomes increased.
To overcome the above-described drawbacks, a structure using a through silicon via (TSV) has been implemented. In an exemplary package, TSVs are formed in each of the stacked chips at a wafer level, and then the chips are stacked on top of one another and physically and electrically connected through vertical TSVs.
However, the TSVs are exposed to heat in subsequent processes such as an annealing process, as well as mechanical stress. When chips are stacked, a bonding process may expose lower surfaces of a semiconductor to, for example, copper ions. Ions may then migrate through the semiconductor to gather in active regions. The gathered metal material acts as a minority carrier generation and recombination center, which causes a leakage current, thereby degrading electrical characteristics of the semiconductor package.